1. Field of the Invention
The present invention relates to rendering print or fax jobs in a multi-printer environment. In particular, the present invention relates to systems and methods for load balancing toner use by printer devices of a multi-printer environment (e.g., printer pool or other multi-printer environment), such that the printer devices more evenly consume their respective toner in the rendering of print or fax jobs.
2. Background and Related Art
Current printing techniques allow for printing to occur in a number of system configurations. For example, one system configuration includes a printer pool, wherein a pool of printers is available for use in rendering print jobs. Printer pools are currently implemented in a variety of manners, including: being virtual driver based, spooler/print processor based, port based, server based and firmware based.
In one example of a printer pool, jobs are allocated to the first available printer, where availability may be defined as the higher of: (i) Ready To Print; (ii) Ready to Print—Warming Up; (iii) Ready to print—Power Save; or (iv) Busy. Some techniques may take into account the warm up and power up times and time to availability for busy printers by estimating when the printers will complete their current job load. Using such techniques, a more even distribution of jobs is obtained over the printer pool, resulting in shorter wait times and higher throughput.
While the utilization of printer pools is currently available for the rendering of print jobs, problems currently exist. For example, as a printer pool is used, the print load averaged over time is typically less than the maximum capacity of the pool. Accordingly, all of the printers of the pool are not actively printing all of the time. Instead, a preferred printer is used more than other printers in the printer pool, which leads to an uneven distribution of toner consumption in the printer pool. The uneven distribution of toner consumption occurs due to an unequal distribution of load over time, wherein print jobs are distributed based on the printer availability.
These problems with the current techniques are illustrated by the following example: Consider a printer pool of three printers, wherein each printer has the same load capacity, which is designated as “L”. Accordingly, in this example, the load capacity of the printer pool would be 3L. If the average aggregate load on the printers is 1.75L, then the average distribution of load on the printer pool may be:
Printer 1100% capacityPrinter 2 50% capacityPrinter 3 25% capacity
In the above example, preference is given to printer 1. If printer 1 is busy (100/175=57%), then the job is sent to printer 2. If printer 2 is busy (50/175=28%), then the job is sent to printer 3. Given this distribution, and a toner life of 30 days at 100% load capacity, the printers will consume their respective toners in the following time periods:
Printer 1 30 daysPrinter 2 60 daysPrinter 3120 days
In the current example, the 3 printers will exhaust their toner at substantially different times, which leads to extra overhead in maintaining the printers. In the above example, the toner cartridges have to be changed at three separate times. This means that if the toner of the printers is maintained by an outside service, the service company will have to come on-site on three separate occasions. Additionally, by an uneven consumption of toner, it is difficult to predict and maintain ‘just enough’ extra toner supply on site. If the predictive amount is incorrect, additional toner may need to be purchased outside of normal purchase cycles.
An uneven consumption of toner can also lead to poor output quality on one or more printers in a printer pool or printer group (e.g., copy and job splitting). If the pool selection is based only on availability, a large print job could be sent to a printer that is low on toner. In this case, the toner may become exhausted before the job is printed, or the amount of toner laid on the paper may increasingly diminish throughout the job.
Thus, while techniques currently exist that are used to render print jobs using a printer pool, challenges still exist, including an uneven distribution of toner consumption in a printer pool. Accordingly, it would be an improvement in the art to augment or even replace current techniques with other techniques.